On Wed, Mar 23, 2022 at 12:30 PM Charlemagne Lasse
<charlemagnelasse@xxxxxxxxx> wrote:
>
> > @@ -75,9 +77,9 @@ do { \
> > */
> > #define __WARN_FLAGS(flags) \
> > do { \
> > + __auto_type f = BUGFLAG_WARNING|(flags); \
> > instrumentation_begin(); \
> > - _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
> > - annotate_reachable(); \
> > + _BUG_FLAGS(ASM_UD2, f, ASM_REACHABLE); \
> > instrumentation_end(); \
> > } while (0)
>
> This causes following sparse warning on x86:
>
> make allnoconfig && touch init/version.c && make CHECK="sparse
> -Wshadow" C=1 init/version.o
> #
> # No change to .config
> #
> CALL scripts/checksyscalls.sh
> CALL scripts/atomic/check-atomics.sh
> CHK include/generated/compile.h
> CC init/version.o
> CHECK init/version.c
> init/version.c: note: in included file (through
> include/linux/rculist.h, include/linux/pid.h, include/linux/sched.h,
> include/linux/utsname.h):
> ./include/linux/rcupdate.h:1007:9: warning: symbol 'f' shadows an earlier one
> ./include/linux/rcupdate.h:1001:47: originally declared here
Thanks for the report. There was already a fix sent for this:
https://lore.kernel.org/lkml/20220317065743.8467-1-mailhol.vincent@xxxxxxxxxx/
but it doesn't mention that sparse is warning about this, too.
I think if Vincent sent a v3 that mentioned that sparse is warning
about this, too, and cc'ed you, you could then supply
signed-off/tested-by tags (or just do so on v2, though it doesn't
mention sparse), and maybe Josh would be so kind as to pick that up?
>
>
> Affected versions (from the ones on kernel.org):
>
> * 5.17 - bfb1a7c91fb7 ("x86/bug: Merge annotate_reachable() into
> _BUG_FLAGS() asm")
> * 5.16.17 - fe0c95903a68 ("x86/bug: Merge annotate_reachable() into
> _BUG_FLAGS() asm")
>
> Cannot be seen when changing the variable name:
>
> diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
> index bab883c0b6fe..cbd11e38252a 100644
> --- a/arch/x86/include/asm/bug.h
> +++ b/arch/x86/include/asm/bug.h
> @@ -77,9 +77,9 @@ do { \
> */
> #define __WARN_FLAGS(flags) \
> do { \
> - __auto_type f = BUGFLAG_WARNING|(flags); \
> + __auto_type __f = BUGFLAG_WARNING|(flags); \
> instrumentation_begin(); \
> - _BUG_FLAGS(ASM_UD2, f, ASM_REACHABLE); \
> + _BUG_FLAGS(ASM_UD2, __f, ASM_REACHABLE); \
> instrumentation_end(); \
> } while (0)
--
Thanks,
~Nick Desaulniers
